What are viral hemorrhagic fevers?

Viral hemorrhagic fevers (VHFs) are illnesses caused by several types of viruses. Some of these viruses cause mild illness. Many others lead to life-threatening diseases with no known cures. One of the best known of this group is yellow fever. Another is the Ebola virus.

Viral hemorrhagic fevers are rare in the U.S. They generally occur in Africa, South America, and Asia, and in travelers to these areas. People in these areas who are most at risk are those who do animal research, healthcare workers and people caring for patients where outbreaks are occurring.

What causes viral hemorrhagic fevers?

These illnesses are caused by viruses from 4 groups:

• Arenaviruses

• Filoviruses

• Bunyaviruses

• Flaviviruses

These viruses infect insects or rodents. You can become infected from exposure to the body, body fluids, or the droppings of an infected rodent or through an insect bite, usually from a mosquito or tick. Some of the viruses also spread from person to person. Viruses can also be spread if you crush an infected tick.

What are the symptoms of viral hemorrhagic fevers?

The symptoms vary by the specific disease. Each person may also have slightly different symptoms. Various organs in the body can be affected. Symptoms often include:

• Fever

• Fatigue

• Dizziness

• Muscle aches

• Loss of strength

• Exhaustion

People with severe cases often show signs of bleeding. This may be under the skin, in internal organs, or from body openings, such as the mouth, eyes, or ears. But blood loss is rarely the cause of death. These people may also have:

• Shock

• Seizures

• Nervous system failure

• Coma

• Delirium

• Kidney failure

The symptoms may look like other health problems. Always see your healthcare provider for a diagnosis.

How are viral hemorrhagic fevers diagnosed?

Your healthcare provider will ask about your past health and travel history. You will also need a physical exam. Blood tests can also help in the diagnosis.

How are viral hemorrhagic fevers treated?

Generally, there is no known cure or treatment for these diseases. People with these illnesses may get supportive treatment. This may include getting fluids or assistance with breathing and pain relievers. An antiviral medicine may help some people with Ebola and Lassa fever.

What can I do to prevent viral hemorrhagic fever diseases?

No vaccines are available to prevent most of these diseases. But there are vaccines for yellow fever, Ebola, and Argentine hemorrhagic fever. It's important to get vaccinated for these when possible or if you will be at high risk for the infections. But it's also important to stay away from the rodents or insects that carry the virus. Before travel, check with your healthcare provider or the CDC website to see if there is viral hemorrhagic fever in the area you are traveling to. Ask if you can be vaccinated to help prevent the infection. For travel to some countries, you must be vaccinated against these viral infections before you can enter them. Travelers should not go to areas where there are outbreaks. Current outbreaks can be identified through the CDC's Travelers Health site https://wwwnc.cdc.gov/travel/notices. The World Health Organization (WHO) also publishes updates on regional and global outbreaks https://www.emro.who.int/pandemic-epidemic-diseases/outbreaks/index.html.

• Control the number of rodents.

• Prevent them from entering or living in homes or workplaces.

• Learn how to safely clean up nests and droppings.

For viruses spread by ticks or mosquitoes, prevention focuses on:

• Controlling mosquitoes and ticks in your environment

• Using insect repellent, correct clothing, bed nets, window screens, and other insect barriers to prevent being bitten

If you are traveling to an area where there is risk for viral hemorrhagic fevers:

• Wear long sleeves and long pants treated with permethrin.

• Use insect repellent.

• Use bed nets in areas where outbreaks are occurring.

• Prevent contact with livestock or rodents in areas where outbreaks are occurring.

Key points about viral hemorrhagic fever diseases

• Viral hemorrhagic fevers are illnesses caused by several groups of viruses. They can be mild or life-threatening. Many have no known cure.

• These viruses live in animals, often in rodents. People can become infected if they come into contact with an infected animal or person. They may also get the disease if they are bitten by a mosquito or tick carrying the virus.

• No cure or treatment is available for most of these illnesses. People should not travel to areas where there are active outbreaks.

• Prevention includes getting vaccinated if you may be exposed to yellow fever, Ebola, or Argentine hemorrhagic fever. Also wear protective clothing, prevent insect bites, and stay away from infected rodents.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

• Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your healthcare provider if you have questions, especially after office hours or on weekends.